Method and apparatus for storing and delivering liquid color materials

ABSTRACT

A container of liquid color material has a diaphragm liquid color pump located therewithin for providing liquid color from the container and non-drip apparatus for releaseably connecting the container with a blender for supply of liquid color thereto and methods for pumping and supplying liquid color incorporating the same. In some embodiments a volumetric controller is utilized for driving and regulating the pump.

CROSS-REFERENCE TO RELATED PATENT APPLICATIONS

This patent application is a 35 USC 120 continuation of Ser. No.10/856,422, filed 28 May 2004 now abandoned in the name of Stephen B.Maguire, which claimed the benefit of U.S. provisional application Ser.No. 60/474,066 filed 28 May 2003 in the name of Stephen B. Maguire for“Liquid Color Pumping Method and Supply Apparatus”, the priority ofwhich is claimed under the applicable provisions of 35 USC 119 and 120.

BACKGROUND OF THE INVENTION—FIELD OF THE INVENTION

This invention relates to methods and apparatus for handling liquidcolor material used to impart color to molded and extruded plasticobjects.

BACKGROUND OF THE INVENTION—DESCRIPTION OF THE PRIOR ART

Liquid color material for use in plastics material processing isconventionally shipped either in five gallon pails, which are typicallyplastic, or in thirty gallon drums, which may be either steel orplastic, or in “totes”, which are large rectangular plastic containersabout forty-two inches along one side and which may hold up to 2,400pounds of liquid color material.

The smaller containers, namely the five gallon pails and the thirtygallon drums, are generally not returned by the purchasers to the liquidcolor material suppliers. However, the totes are nearly always returned.

It is beneficial for purchasers to return the totes to the liquid colormaterial supplier since return eliminates any environmental problemwhich might otherwise be encountered by the purchaser through disposalof empty totes. Additionally, unused liquid color material in the bottomof the tote or sticking to the sides of the tote can be weighed andcredited to the purchaser, since the tote will be refilled and soldagain with the same color material.

SUMMARY OF THE INVENTION

In one of its aspects, this invention provides a low cost liquid colorpump which preferably may be positioned in a liquid color materialshipping container, which may include a liquid-tight disconnect,allowing provision of the liquid color output from the pump directly orindirectly to a plastics material processing machine in which the liquidcolor preferably imparts color directly to plastic parts beingmanufactured or to plastic resin material being blended for subsequentfabrication such as by injection or compression molding or by extrusion.An air line may power the pump within the container and is desirablyconnected to a source of pressurized air.

In accordance with the invention, liquid color containers are desirablysealed at the liquid color factory so that a purchaser of the liquidcolor material preferably never opens the container or has any access tothe liquid color material in the container, except through preferablyself-sealing quick disconnect connections which preferably shut off whendisconnected, thereby preventing liquid color outflow from thecontainer.

Desirably, a pump in accordance with the invention is a diaphragm pump,preferably generally cylindrical in shape, and preferably on the orderof about three inches (3″), which is about seven and one-half (7.5)centimeters, in diameter by about one and one-half inches (1-½″), whichis about two (2.0) centimeters, thick. Most desirably, a preferably flatdiaphragm is sandwiched between a pump upper portion and a body havingan exterior which is preferably in the general shape of a cylinder. Thebody desirably has an open interior defined by a cavity which preferablystep-wise tapers down from a relatively large size to a liquid inletaperture preferably located in the center of the bottom of the body. Aball, desirably about three quarters (¾) of an inch, which is about two(2.0) centimeters, in diameter is movable vertically and seats on theinlet aperture at the bottom of the open interior cavity, acting as acheck valve allowing liquid to enter, but not leave, through the inletdefined by the aperture. An outlet port is formed in the side of thepump body.

Desirably a spring within the pump biases the diaphragm in a directionaway from the open interior cavity.

A pneumatically driven piston rod extension desirably reciprocablydisplaces the diaphragm towards the open interior cavity, displacingliquid color from the pump open interior cavity out through the outletaperture. The spring desirably returns the diaphragm at least to thediaphragm original flat or neutral position and preferably past suchneutral position, thereby sucking in liquid color through the inletaperture which is preferably directly below the diaphragm.

In another one of its aspects, this invention provides apparatus forfurnishing liquid color on demand to one or more plastics processingmachines where the apparatus includes a closeable container having atleast one outlet which is preferably self-sealing, with preferably adiaphragm pump connected to and housed within the container interior forpumping liquid out of the container via the outlet connection,responsive to pressurized gas. The closeable container is preferablydifficult, indeed preferably nearly impossible, for the customer toopen. This feature in combination with the self-sealing outlet minimizesthe likelihood of the liquid color customer spilling any significantamount of liquid color material in the customer's plastics materialprocessing facility.

In yet another one of its aspects, this invention provides apparatus forfurnishing liquid color on demand where the apparatus includes acontainer preferably having a quick-disconnect, self-sealing outletconnection. Preferably, the apparatus further includes a pneumaticpiston-cylinder combination removably connected to the container andadapted for pneumatically-driven reciprocation of an output shaftportion of the combination. The apparatus further preferably includes areciprocable rod within the container with a first end of the rod beingadapted for reciprocating driving of the rod by an output shaft of thepiston-cylinder combination. The apparatus preferably further includesdiaphragm pump means connected to and housed at least partially, andpreferably wholly, within the container for pumping the liquid color outof the container via the outlet connection. The pump includes adiaphragm and preferably also a spring for biasing the diaphragm awayfrom an open interior cavity portion of the pump. The diaphragmpreferably is displaceable into the open interior cavity portionresponsively to reciprocating motion of the rod, to displace fluid fromthe open interior cavity of a pump body within which the diaphragm ispositioned.

The invention may further embrace means for releasably retaining thepiston-cylinder combination in position on the container forreciprocating contact of the piston-cylinder combination with the rod,where the releasable retaining means may further include a moveablesleeve connected to the piston-cylinder combination. The sleevedesirably has at least one slot preferably extending first axially awayfrom the terminus of the sleeve, towards the piston-cylindricalcombination and preferably then in an annular direction partially aroundthe sleeve.

In yet another of its aspects this invention may embrace a method forfurnishing liquid color to a plastics resin processing machine where themethod includes providing a preferably closed container having at leastone outlet connection with the container preferably having liquid colormaterial therewithin, pumping the liquid color material out of thecontainer preferably via the outlet connection by pneumatically orpreferably mechanically reciprocating a diaphragm to displace thediaphragm into a body including an open interior cavity thereby forcingliquid color material within the body preferably through an aperture inthe body and out of the container via the outlet connection.

In yet another of its aspects, this invention embraces a liquid colordiaphragm pump where the pump preferably includes a body having a cavityformed therein and a cover connected to the body. A flexible diaphragmpreferably separates the cover from the cavity. The cover has a relieflocated proximate to the portion of the diaphragm which separates thecover from the cavity, with the relief providing space between the coverand the diaphragm. The pump further includes means for cyclicallydisplacing the diaphragm away from the relief area of the cover and intothe cavity. The pump preferably further includes means for biasing thediaphragm away from the cavity, towards the relief area of the cover andpreferably into the space thereunder during a portion of eachreciprocating cycle of diaphragm displacement.

Desirably, the means for cyclically displacing the diaphragm is areciprocating means and contacts the diaphragm. Further desirably, themeans for biasing the diaphragm away from the cavity is a spring, mostpreferably a coil spring. The body of the pump preferably has apassageway connecting a body bottom surface to the cavity with at leasta portion of the passageway being substantially vertical and the pumpfurther comprising a freely vertically moveable ball residing within thecavity vertical portion for blocking downward liquid flow within thecavity vertical portion. The vertically freely moveable ball ispreferably resident within the spring so that the spring constrains theball against lateral movement.

In another aspect of the invention, disclosed herein is an apparatus andmethod for supplying liquid color to a plastic resin processing machine.In some embodiments of this aspect of the invention, the apparatus andmethod include a closed container and a pump within the container. Thepump comprises a housing having a cavity formed therein, a diaphragmdisplaceable into the cavity for urging liquid color out of the cavityvia an outlet passageway through the housing, and a reciprocable rodextending into the housing for displacing the diaphragm into the cavity.The apparatus and method also involve a drive outside the container forreciprocating the rod. The drive comprises a motor having an outputshaft, a cam connected to the shaft for rotation thereby, and a followerpositioned in riding contact with the cam, movable transverselyrespecting the shaft responsively to rotation of the cam and connectedto the rod to reciprocate the rod thereby displacing the diaphragm.

In this aspect of the invention some embodiments include self-sealingmeans connected to the outlet passageway at the exterior of thecontainer for preventing flow of liquid color out of the container viathe outlet passageway upon disconnection of the apparatus from a liquidcolor user. Some embodiments have a spring-loaded, preferably manuallyactuable quick-disconnect as the self-sealing means. In someembodiments, there is liquid color in the container. Depending on theembodiment, the motor may be pneumatically, hydraulically, electricallyor mechanically driven. In some embodiments of this aspect of theinvention, the reciprocating rod contacts the diaphragm.

In this aspect of the invention some embodiments include the pumpcomprising means for biasing the diaphragm away from the cavity, duringa portion of a cycle of diaphragm displacement. These means may comprisea coil spring. In some embodiments, the housing has an inlet passagewayconnecting a pump exterior surface to the cavity, with at least aportion of the passageway being substantially vertical, with the pumpfurther comprising a freely vertically movable ball residing in thepassageway vertical portion, for blocking liquid color flow downwardwithin the passageway and out of the pump. In some embodiments, the ballis within the spring and/or the spring constrains the ball againstlateral movement.

In some embodiments, the pump exterior surface is a bottom surface ofthe pump housing. An outlet passageway leads from a vertical extremityof the cavity to the exterior of the pump for conveyance of liquidcolor, displaced from the cavity by the diaphragm, out of the pump. Theapparatus may include an outlet passageway communicating with the cavityadjacent to the diaphragm and leading to the exterior of the pump forconveyance of liquid color displaced from the cavity by the diaphragmout of the pump. In some embodiments, the outlet passageway has avertical portion and the pump further comprises a freely verticallymovable ball residing in the outlet passageway vertical portion, forblocking liquid flow downward within the outlet passageway and into thepump.

In some embodiments of the invention, the apparatus and methods includea drive control means for actuating the motor. The drive control meanspreferably comprises an electronic controller and an at least temporarymemory, with the electronic controller programmed to activate the motoraccording to a desired volume of liquid color. In some embodiments, theelectronic controller is adapted to be programmed by either or both auser input device and an external device when connected to an externalconnection of the electronic controller.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic front assembly view, in elevation, with many ofthe parts depicted in section, of a container used for supply of liquidcolor material and having a liquid color pump therewithin, all inaccordance with the invention

FIG. 2 is an enlarged front view in section, showing details ofstructure indicated generally by dotted circle 2 in FIG. 1.

FIG. 3 is a broken exploded partial front view with some parts depictedin section, showing details of a portion of the structure of FIG. 1indicated generally by dotted circle 4A in FIG. 1.

FIG. 4A is an enlarged front assembly view, with most of the parts shownin section, of the structure indicated generally by dotted circle 4A inFIG. 1, with a diaphragm portion of the structure undisplaced.

FIG. 4B is an enlarged front assembly view, similar to FIG. 4A, withmost of the parts shown in section, of the structure indicated generallyby dotted circle 4A in FIG. 1, but with the diaphragm portion of thestructure depicted displaced as when pumping liquid color.

FIG. 5 is a broken sectional front view of the lid portion of thecontainer illustrated in FIG. 1 showing container replacabilitystructure facilitating color on-the-fly switchover in accordance withthe invention.

FIG. 6 is a broken partially schematic view of dripless liquid colorconnection apparatus adapted for attachment to a gravimetric blender orother device for serial supply of liquid color material to the blenderor other device and adapted for on-the-fly changeover from an emptyliquid color container to a full liquid color container withoutinterruption of the production of plastic parts from the plastic resinof which the liquid color is an ingredient, in which only one connectorfor a liquid color container is illustrated, disengaged from theconnection apparatus.

FIG. 7 is a broken partially schematic view of the liquid colorconnection apparatus illustrated in FIG. 6 and looking in the samedirection as in FIG. 6 but showing one tubular connector from a liquidcolor container engaged with the connection apparatus.

FIG. 8 is a schematic side elevation of a gravimetric blender connectedto two closeable containers of liquid color material with liquid colordiaphragm pumps therewithin.

FIG. 9 is a partially exploded isometric view showing a volumetriccontroller specifically adapted for modification of the apparatusillustrated in FIG. 1.

FIG. 10 is a similarly partially exploded side view of the volumetriccontroller shown in FIG. 9.

FIG. 11 a is a side view of the volumetric controller shown in FIG. 9with a roller in an upward position.

FIG. 11 b is a side view of the volumetric controller shown in FIG. 9with a roller in a downward position.

FIG. 12 is a cross-sectional view of a volumetric controller taken at12-12 in FIG. 11 b.

FIG. 13 is a block diagram schematic of an electronic control means forpractice of aspects of the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS AND BEST MODE KNOWN FORPRACTICING THE INVENTION

The disclosures of U.S. Pat. No. 6,007,236 and corresponding PatentCooperation Treaty Patent Application PCT/US96/19485 published asWO97/21528 are incorporated by reference herein.

Referring to the drawings in general and to FIG. 1 in particular,apparatus for furnishing liquid color material to a plastic resinprocessing machine is designated generally 10. Apparatus 10 includes acloseable container 12 preferably having a quick disconnect self-sealingoutlet connection 14. Closeable container 12 includes a lid 46 and abody 104. Lid 46 is preferably secured to body 104 in a manner thatremoval of lid 46 from body 104 by a purchaser of liquid color materialwithin container 12 is difficult. This may be accomplished bymechanically crimping, cementing, welding or otherwise securing theperiphery of lid 46 to illustrated angularly upwardly extending lipportions 47 defining the upper extremities of body 104.

A diaphragm pump is designated generally 18 and is positioned withincloseable container 12 as illustrated in FIG. 1. Diaphragm pump 18includes a body 24 which is preferably generally cylindrical andpreferably has an open interior cavity portion 26 (not marked in FIG. 1but clearly indicated in FIG. 3). Inlet aperture 30, best shown in FIGS.3, 4A and 4B, is formed in a downwardly facing bottom exterior surface118 of pump body 24 and serves as an inlet for liquid color materialentering diaphragm pump 18. Body 24 may be molded plastic material ormay be machined from a solid block of metal.

As best shown in FIG. 1, diaphragm pump 18 preferably contacts and restson the interior surface 114 of the bottom 116 of container body 104.Most desirably, downwardly facing bottom exterior surface 118 of pumpbody 24 is closely spaced from interior surface 114 of bottom 116 ofcontainer body 104 by the heads of bolts 100, which secure diaphragmpump 18 together, resting on interior surface 114. The resulting closespacing of downwardly facing pump bottom exterior surface 118 fromcontainer upwardly facing interior surface 114, which spacing preferablyis on the order of one-quarter (¼) inch or less, assures that diaphragmpump 18 evacuates substantially all liquid color material withincontainer 12 before container 12 is recycled.

Referring principally to FIGS. 1 and 3, bolts 100 threadedly engage nuts102 thereby securing the assembly of diaphragm pump 18 together. Bolts100 pass through bores formed in pump body 24, a flexible diaphragm 36located along and in facing contact with an upper surface 120 of pumpbody 24, and a pump upper plate portion 23, to secure diaphragm pump 18together, with assembly being effectuated in manner shown in theexploded view of FIG. 3. The bores through which bolts 100 pass in pumpbody 24, diaphragm 36 and pump upper plate portion 23 are notillustrated in the drawings to facilitate drawing clarity. Diaphragmpump 18 in its assembled form, secured together by bolts 100 and nuts102, is illustrated in greater detail in FIGS. 4A and 4B.

As best shown in FIGS. 3, 4A and 4B, within pump body 24 an inlet checkvalve 34 is positioned within inlet aperture 30. Inlet check valve 34includes a ball 35 biased by its own weight against a conical seatportion 84 of an inlet passageway 80 leading into pump body 24 frominlet aperture 30. An inlet passageway formed in pump body 24 andleading to open interior cavity portion 26 is designated generally 80 inFIG. 3 and commences at first or inlet aperture 30 formed in downwardlyfacing exterior bottom surface 118 of pump body 24. Inlet passageway 80has a first minor cylindrical portion 82 bordering first or inletaperture 30.

Still referring principally to FIGS. 3, 4A and 4B, inboard of firstminor cylindrical portion 82 in inlet passageway 80 is a conical seatportion 84 formed in pump body 24, which tapers to enlarge passageway 80from a relatively small diameter at inlet aperture 30 to a largerdiameter, which is not numbered in the drawings. Conical seat portion 84terminates at a second intermediate cylindrical portion 86 of inletpassageway 80; second intermediate cylindrical portion 86 is preferablyof larger diameter than the maximum diameter of conical seat portion 84.

Second intermediate cylindrical portion 86 in turn leads to third majorcylindrical portion 88 which, together with second immediate cylindricalportion 86 and conical diaphragm receiving portion 90, discussed below,largely defines an open interior cavity portion 26 of pump body 24. Asillustrated in FIG. 3, axial length of third major cylindrical portion88 preferably exceeds axial length of second intermediate cylindricalportion 86 as well as the individual axial lengths of conical seatportion 84 and first minor cylindrical portion 82. Third majorcylindrical portion 88 terminates at juncture with conical diaphragmreceiving portion 90 which in turn tapers from the diameter of thirdmajor cylindrical portion 88 to an even larger diameter at a preferablyplanar upper surface 120 of pump body 24 of diaphragm pump 18.

Referring principally to FIGS. 1, 3, 4A and 4B, a coil spring 38 resideswithin inlet passageway 80 and fits slidably about ball 35. Coil spring38 constrains ball 35 against significant lateral movement within inletpassageway 80 but preferably does not bias ball 35 vertically. Coilspring 38 preferably seats on an annular surface defining the lowerboundary of second intermediate cylindrical portion 86 which in turndefines a portion of inlet passageway 80. The annular surface on whichspring 38 seats is designated 130 in FIG. 3 and is radially outboard ofand defines the maximum diameter and hence terminals of conical seatportion 84 of inlet passageway 80.

The end of spring 38 opposite that which seats on annular surface 130carries a spring cap 96 which includes hollow cylindrical body portion106 and a solid planar top portion 108, as illustrated in FIG. 3. Hollowcylindrical body portion 106 preferably fits in contact with theinterior of coil spring 38, with coil spring 38 abutting an unnumberedannular downwardly facing surface of solid planar top portion 108 ofspring cap 96.

Still referring principally to FIGS. 3, 4A and 4B, spring cap 96facilitates constant application of bias by spring 38 against lowersurface 126 of diaphragm 36. Spring 38 is preferably selected withspring constant and dimensions such that spring 38 continuously biasesdiaphragm 36 upwardly, against a preferably circular flange 58, in amanner that diaphragm 36 and flange 58 are constantly in facing contactone with another. The positions of diaphragm 36, flange 58, spring 38and spring cap 96, when diaphragm 36 is in the extreme upward position(and still in contact with flange 58) are illustrated in FIG. 4A; theposition of these components when diaphragm 36 is in the extremedownward position (at which diaphragm 36 is still in contact with flange58) is illustrated in FIG. 4B. Hence, FIGS. 4A and 4B illustrate therespective limits of travel and limits of flexure of diaphragm 36 duringreciprocation of an actuator rod 56 as reciprocably driven by apiston-cylinder combination 60. In FIG. 4B, double arrows A denotedownward force exerted by actuator rod 56 via flange 58 on diaphragm 36,where such downward force has overcome the upwardly directed force ofspring 38 and any resilient resistive force resulting from deformationof diaphragm 36 away from its neutral, unflexed position. The neutral,unflexed position of diaphragm 36 has not been illustrated in thedrawings.

First inlet check valve is designated generally 34 and is defined byball 35 contacting conical seat 84.

Pump body 24 includes an intermediate outflow passageway 92 leading fromopen interior cavity portion 26 to an intermediate vertical chamber 40,which in turn opens into an outlet passageway 33 for discharge of liquidcolor material pumped by diaphragm pump 18. The entrance to intermediateoutflow passageway 92 is desirably located in an upper extremity of asurface bounding open interior cavity portion 26 of pump body 24, asillustrated in FIG. 3. This positioning minimizes risk of any airbubbles which may form in open interior cavity portion 26 beingdelivered with the liquid color by the pump. The outlet from diaphragmpump 18 is defined by an outlet aperture 32. An outlet fitting 122 isillustrated connecting with outlet aperture 32 in FIG. 3.

Desirably an outlet check valve is designated generally 42 and has aball 43 seating vertically, due to force of gravity, against apreferably conical seat 110 present in vertically elongated intermediatechamber 40 formed in valve body 24. Outlet check valve 42 ensures thatliquid color material only travels in one direction, namely outwardly,through outlet passageway 33. Ball 43 is moveable freely in the verticaldirection. Weight of ball 43 seats ball 43 on conical seat 110. Force ofliquid color moving through intermediate outflow passageway 92 intointermediate vertically elongated chamber 40 lifts ball 43 from conicalseat 110. Any attempt by liquid color material to flow from intermediatechamber 40 back into intermediate outflow passageway 92 is precluded asball 43 comes to rest on conical seat 110.

A coil spring 44 within chamber 40 desirably fits about ball 43 andconstrains ball 43 from lateral movement within vertically elongatedintermediate vertical chamber 40. Spring 44 preferably does not exertany vertical force on ball 43; preferably ball 43 is vertically freelymoveable within the interior of coil spring 44 in chamber 40. Spring 44,by precluding lateral movement of ball 43, reduces the likelihood ofball 43 sticking and thereby rendering outlet check valve 42 inoperable.

First inlet check valve designated generally 34, defined by ball 35contacting conical seat portion 84, assures that liquid color materialentering open interior cavity portion 26 of pump body 24 exits pump body24 via outlet passageway 33 and outlet aperture 32, not via inletaperture 30 and inlet passageway 80.

Diaphragm 36 is moved in a first direction, downwardly considering thedrawings, towards and into open interior cavity portion 26 by a flange58 contacting an upper surface 124 of diaphragm 36. Lower surface 126 ofdiaphragm 36 faces open interior cavity portion 26 in pump body 24.Flange 58 is preferably secured to an end of actuator rod 56 asillustrated in FIGS. 1, 3, 4A and 4B. A flange support spacer 59 ispreferably fixed to the upper surface of flange 58 and to the portion ofactuator rod 56 immediately adjacent flange 58 and provides a bearingsurface between actuator rod 56 and the interior surface of a cylinder54. Preferably flange support spacer 59 is a solid plastic materialhaving good lubricity.

Actuator rod 56 is housed reciprocably within a container interiorcylinder 54, which is a hollow tube preferably connected at one end topump upper plate portion 23 of diaphragm pump 18 as illustrated inFIG. 1. Actuator rod 56 is preferably connected at its opposite end tolid 46 of closeable container 12, as illustrated in FIGS. 1 and 2.

The end of actuator rod 56 opposite that at which flange 58 is affixedis adapted for abutting contact by a rod 66 extending from apiston-cylinder combination 60 as illustrated in FIGS. 1 and 2.Piston-cylinder combination 60 is preferably a commercially availablepneumatically driven piston-cylinder combination such as that sold underthe trademark “SMC Cylinder”. Piston-cylinder combination 60 receivespressurized air, via a hose designated 74 in FIG. 1, and an interiorpiston, not shown in the drawings reciprocates in response to thepressurized air. The reciprocating interior piston is mechanicallyconnected to rod 66 so that rod 66 reciprocates unitarily with thereciprocating interior piston. Reciprocating motion provided by theinterior piston of piston-cylinder combination 60 works to reciprocateactuator rod 56 through abutting contact thereof with rod 66 extendingfrom piston-cylinder combination 60. Hence, reciprocation of theinterior piston portion of piston-cylinder combination 60 results inreciprocation of flange 58, preferably in the vertical direction asillustrated in the drawings.

Referring to FIG. 2, preferably pneumatically powered piston-cylindercombination 60 is desirably equipped with a hollow cylindrical adapter62 extending co-axially from piston-cylinder combination 60 with rod 66.Adapter 62 is preferably fixedly connected to piston-cylindercombination 60; adapter 62 does not move relative to piston-cylindercombination 60 as rod 66 reciprocates.

A coil spring 68 is located at the distal end of container interiorcylinder 54 relative to diaphragm pump 18 and is retained in positionwithin container interior cylinder 54 by screws 70 driven through thewall of cylinder 54 as illustrated in FIG. 2. Spring 68 is compressed ina vertical direction considering FIG. 2 by contact with a lower annularextremity surface 73 of a cylindrical bushing 76, the interior of whichprovides a sliding bearing surface for actuation rod 56. Bias of spring68 against lower annular extremity surface 73 of cylindrical bushing 76serves to bias bushing 76 upwardly, urging an upper cylindrical surfaceof bushing 76 against a lower extremity of stationary cylindricaladaptor 62 thereby retaining bushing 76 in position for slidingreciprocating contact therewith by actuator rod 56 as rod 56reciprocates. The bias applied continuously by spring 68 to bushing 76prevents “slop” from developing over time in the assembly illustrated inFIG. 2 as rod 56 reciprocates. The bias also facilitates quickconnection and disconnection of piston-cylinder combination 60 to andfrom container 12, as described below.

A pair of radially opposed positioning screws 64 extend radiallyinwardly within container interior cylinder 54, at a position close tobut somewhat removed from the upper extremity thereof as illustrated inFIG. 2. Cylindrical adapter 62 has a pair of vertically elongatedradially opposed slots which open vertically downwardly into lowerannular extremity surface 72 of adapter 62. Those slots, which are notvisible in FIG. 2, are not illustrated elsewhere in the drawings andhence do not have indicator numerals associated therewith. The slotsextend axially within cylindrical adapter 62 away from lower annularextremity surface 72 and then turn ninety degrees (90°) and extend ashort distance angularly around cylindrical adapter 62. These slotsextend entirely through the wall of cylindrical adapter 62. These slotsare configured similarly to slots 158 illustrated in FIG. 6.

The slot configuration facilitates easy installation of piston-cylindercombination 60 on container 10. When piston-cylinder combination 60 ispositioned so that cylindrical adapter 62 is inserted downwardly intothe open interior of cylinder 54, the openings of the slots formed inlower annular extremity surface 72 of cylindrical adapter 62 mayinitially engage positioning screws 64; if they do not engage, slightmanual rotation of cylindrical adaptor 62 effectuates their engagement.

During installation, as cylindrical adapter 62 is manually forceddownwardly in FIG. 2 against upward force exerted on bushing 76 by coilspring 68, with the axially extending portions of the slots incylindrical adapter 62 engaged by screws 64, once adapter 62 has movedsufficiently downwardly (in FIG. 2) that spring 68 is adequatelycompressed, piston-cylinder combination 60 and cylindrical adapter 62may be manually rotated, causing the angular or circumferential portionsof the unnumbered slots to engage screws 64. Once this manual rotationis complete and downward (considering FIG. 2) manual force onpiston-cylinder combination 60 and cylindrical adapter 62 is released,spring 68 urges piston-cylinder combination 60 vertically upwardly(considering FIG. 2). This causes the angular extremity surfaces of theslots to contact lower surfaces of screws 64 thereby securingpiston-cylinder combination 60 and adapter 62 securely in place.

To assure the post-installation retention of piston-cylinder combination60 in position, the angular extremity portions of the slots, at the endsremote from juncture with the axially extending portions of the slots,similar to slots 158 illustrated in FIG. 6, preferably have smallundercuts therein extending axially away from piston-cylindercombination 60. These undercuts receive screws 64 and positively retainscrews 64 in place, as the vertically upward force is applied topiston-cylinder combination 60 via spring 68 biasing cylindrical adaptor62 upwardly in FIG. 2.

To remove piston-cylinder combination 60 from container 12, the sequencedescribed above is reversed.

As illustrated in FIG. 2, the upper extremity of container interiorcylinder 54 desirably is in abutting contact with the lower interiorsurface of lid 46 of container 12. Container interior cylinder 54 ispreferably secured to lid 46 in some permanent fashion, for example bywelding. As a result, when piston-cylinder combination 60 and adapter 62are removed through application of angular and axial manual force topiston-cylinder combination 60, container interior cylinder 54 remainsin place, being preferably fixedly secured to the interior of lid 46.Desirably, a liquid-tight fitting 98 of generally annular shape isprovided about the exterior of container interior cylinder 54 at theposition of juncture with lid 46 as illustrated in FIG. 2; this assuresliquid-tight sealing about container interior cylinder 54 at theposition of juncture with lid 46. It is further desirable that a stopperor other device be provided to occupy the interior opening of containerinterior cylinder 54 when pneumatic piston-cylinder combination 60 andadapter 62 have been removed. This provides additional assurance againstany leakage of liquid color material out of container 12.

Referring to FIG. 5, which is a broken view mostly in section of theupper portion of container body 104 and lid 46, the quick disconnect,disposable and recyclable coupling associated with container 12 isillustrated. In addition to facilitating quick changeover, the quickdisconnect also enhances the disposable and recyclable characteristicsof the pump-container combination. In FIG. 5, the self-sealing quickdisconnect fitting 14 is shown disconnected, revealing a self-sealingmale portion 136 and a self-sealing female portion 138. Male portion 136is preferably essentially permanently secured to lid 46 of container 12while female portion 138 is preferably connected to a color supply hose139 leading to a gravimetric blender or other device which receives anduses liquid color furnished by diaphragm pump 18. Fitting 14 can bedisengaged by separating female portion 138 from self-sealing maleportion 136 via manual force; any adult of reasonable strength anddexterity can do this. The individual parts of male and female portionsof self-sealing quick disconnect fitting 14 have not been individuallynumbered or described herein since quick disconnect self-sealingfittings, such as designated 14 in the drawings, are well known in theart.

A vent screw 132 is positioned in lid 46 and may be turned manually inthe event atmospheric pressure is needed in container 12 as pump 18evacuates liquid color from container 12.

Still referring to FIG. 5, pneumatically driven piston-cylindercombination 60 and adapter 62 are shown removed from their positions,within lid 46, in which those components are illustrated in FIGS. 1 and2. When piston-cylinder combination 60 and cylindrical adapter 62 areremoved from lid 46, a stopper designated 134 in FIG. 5 is preferablyput in place to guard against contamination entering the open interiorof container interior cylinder 54. As is the case with self-sealingquick disconnect fitting 14, piston-cylinder combination 60 and adapter62 may be manually engaged with or disengaged from container interiorcylinder 54 and actuator rod 56 by any adult of moderate strength.

To operate diaphragm pump 18, piston-cylinder combination 60 is actuatedby application of gas, preferably air, thereto via input line 74.Reciprocation of the piston portion of piston-cylinder combination 60causes corresponding reciprocation of piston rod 66. As piston rod 66reciprocates, rod 66 contacts actuator rod 56 thereby causing actuatorrod 56 to reciprocate in the vertical direction considering the drawingfigures. Vertical reciprocation of rod 56 causes corresponding verticalreciprocation of flange 58. Since flange 58 is in contact with uppersurface 124 of diaphragm 36, diaphragm 36 distends downwardly into theopen interior cavity portion 26 of pump body 24.

Advancement of diaphragm 36 into open interior cavity portion 26 of pumpbody 24 increases the pressure of liquid color material residenttherein. This diaphragm displacement and resulting pressure increasecauses liquid color material in cavity portion 26 to flow through liquidcolor intermediate passageway 92, past outlet check valve 42, throughoutlet passageway 33, and out of container 10 via liquid color outletline 50.

During the upward portion of the reciprocation of the interior piston ofpiston-cylinder combination 60 and actuator rod 56, diaphragm 36initially moves towards an unstressed horizontal position in response toforce exerted by spring 38 on spring cap 96 contacting diaphragm 36;continued application of force by spring 38 on spring cap 96 contactingdiaphragm 36 distends diaphragm 36 further upwardly. The resulting voidcreated in open interior cavity portion 26 of pump body 24 causes liquidcolor material to flow by suction through liquid color inlet aperture30, past inlet check valve 34 into open interior cavity portion 26 ofpump body 24. After the interior piston of piston-cylinder combination60 has completed upward movement and commences a new reciprocation bymoving piston rod 66 and hence actuator rod 56 downwardly, again pushingdiaphragm 36 vertically downwardly into open interior cavity portion 26,flange 58 again displaces diaphragm 36 against the force of spring 38into open interior cavity portion 26 and liquid color is again urgedpast outlet check valve 42, through liquid color outlet passageway 33and out of container 10.

While use of a pneumatically driven piston-cylinder combination toreciprocate rod 56 is preferred, an electric motor rotating a cam or agear may also be used, as may a hydraulic motor or a solenoid.

FIGS. 6 and 7 illustrate an embodiment of apparatus for driplesslyconnecting and thereafter furnishing liquid color from container 12 forsubsequent processing where the apparatus is shown in a disconnecteddisposition in FIG. 6 and in a connected disposition in FIG. 7.

Apparatus for driplessly connecting and thereafter furnishing liquidcolor from a container 12 is designated generally 140 in the drawingsand includes a tubular member 142 secured in and passing through amounting plate 146. A set of splash baffles 148 are connected tomounting plate 146 and to tubular member 142 in the area in which theliquid color is released and hence where some splash may occur. Tubularmember 142 is hollow over its entire length; two tubular members 142 areillustrated in the embodiment illustrated in FIGS. 6 and 7. Mountingplate 146 allows apparatus 140 to be fastened, by bolts or by welding,directly to the frame of a gravimetric blender so as to position one ormore liquid color outlet apertures of apparatus 140 for delivery ofliquid color material directly into the weigh bin of the blender.

An inlet end of tubular member 142 is designated 150 and is locatedoutside the liquid color dispensing area, typically being separated fromsuch dispensing area by mounting plate 146. Desirably formed within theannular facing end surface defining inlet end 150 of tubular member 142is a slot 158 preferably configured as shown in FIGS. 6 and 7. Slot 158opens into the annular axially facing surface defining inlet end 150 oftubular member 142. Proceeding axially from that position along tubularmember 142, slot 158 has an axially extending portion followed by anangularly transversely extending portion running at right angles to theaxis of tubular member 142. At the end of the angularly extendingportion, a small axial undercut is formed, as shown in the drawings.Neither the axial nor the angular transverse portions of slots 158, northe undercuts, have been separately numbered in the drawings.

A portion of exterior wall 156 of tubular member 142 is cut away;preferably this is a portion subtending an angle of about one hundredeighty degrees (180°) relative to the axis of tubular member 142. Thiscutaway serves to expose an interior wall portion 154 of tubular member142 as illustrated generally at the top of FIGS. 6 and 7. Within thecutaway portion, a screw 152, serving as a stop, is provided in theremaining wall portion of tubular member 142. The head of screw 152desirably fits into the portion of the wall of tubular member 142 whichwould be the interior thereof, were the facing portion of the wall notcut away.

Apparatus 140 further includes a tubular conduit assembly designatedgenerally 162 in FIGS. 6 and 7. An end plug 166 closes one end oftubular conduit assembly 162. A fluid connecting member 172 ispositioned in the other end of tubular conduit assembly 162 forconnection with a color supply hose 139 leading from closable container12 having liquid color and diaphragm pump 18 located therewithin.

Tubular conduit assembly 162 further includes an axially slidablepreferably cylindrically configured sleeve 164 which is desirably sizedto fit slidably within tubular member 142. Tubular conduit assembly 162preferably further includes a cylindrical spacer 170, which is desirablyfixed to tubular conduit assembly 162 and is also sized for slidingentry into the interior of tubular member 142. A spring 160 ispositioned between cylindrical spacer 170 and slidable sleeve 164 andwraps around a tubular conduit portion 163 of tubular conduit assembly162. Spring 160 biases slidable sleeve 164 in a direction towards thetop of the paper in FIG. 6, away from cylindrical spacer 170.

Extending laterally from cylindrical spacer 170 is a spacer pin 168sized for mating engagement with one of slots 158.

A liquid color outlet aperture 174 is formed in tubular conduit 163proximate the end thereof, adjacent to end plug 166, as shown in FIG. 7.

When dripless connection apparatus 140 is in the configurationillustrated in FIG. 6 where tubular conduit assembly 162 is not residentwithin tubular member 142, tubular conduit liquid color outlet aperture174 is covered by slidable sleeve 164. Desirably, the inner diameter ofslidable sleeve 164 is only slightly larger than the outer diameter ofthe interior conduit portion 163 of tubular conduit assembly 162 so thatliquid color material cannot escape from the interior of conduit 163through aperture 174 when aperture 174 is covered by slidable sleeve164.

Because cylindrical spacer 170 is fixed to tubular conduit 163, spring160 continuously biases slidable sleeve 164 into a position coveringliquid color outlet aperture 174. Accordingly, even though tubularconduit assembly 162 may be connected to a liquid color supply line 139by connecting member 172 and liquid color may be within supply hose 139,until slidable sleeve 164 is moved against the bias of spring 160 andexposes liquid color outlet aperture 174, no liquid color flows fromdripless connection apparatus 140.

When it is desired to supply liquid color, tubular conduit assembly 162is inserted into tubular member 142 in the direction indicated by arrowA in FIG. 6. Slidable sleeve 164 enters tubular member 142 at the inletend 150 thereof and moves slidably through tubular member 142 until aforward annular end surface 176 of slideable sleeve 142 contacts screw152 serving as a stop. As tubular conduit assembly 162 is forced furtherinto tubular member 142, interference between screw 152 and annular endsurface 176 of slidable sleeve 164 precludes further movement ofslidable sleeve 164 in the direction indicated by arrow A in FIGS. 6 and7. However, since the remainder of tubular conduit assembly 162continues to move in the direction of arrow A in FIG. 7, the portion oftubular conduit 162 which is axially adjacent and connected to end plug166 continues to move in the direction of arrow A in FIG. 6, past screw152. This relative motion between the portion of tubular conduitassembly 162 residing within slidable sleeve 164 and slidable sleeve 164itself exposes the portion of tubular conduit 163 in which liquid coloroutlet aperture 174 is located; this is illustrated in FIGS. 6 and 7.

In order to secure apparatus 140 in this position, at which liquid colormay flow freely out of outlet aperture 174, tubular conduit assembly162, conduit 163 and cylindrical spacer 170 are moved manually furtherin the direction indicated by arrow A, against the bias resulting fromspring 160 being compressed between cylindrical spacer 170 and slidablesleeve 164, until spacer pin 168 is in a position to enter slot 158. Atthat position, cylindrical spacer 170 is moved manually slightly axiallyfurther in the direction of arrow A until pin 168 reaches the angularportion of slot 158, whereupon a small manual rotation of cylindricalspacer 170 moves pin 168 into the angular transverse portion of slot158, where the axial undercut is located. This serves to retain tubularconduit assembly 162 in engagement with tubular member 142 in theconfiguration illustrated in FIG. 7, whereby liquid color material maybe delivered via outlet aperture 174.

For drawing clarity, dripless connection apparatus 140 in FIGS. 6 and 7has been illustrated with only a single tubular conduit assembly 162engaging a tubular member 142. However, the invention embraces but isnot limited to use of apparatus such as illustrated in FIGS. 6 and 7 toconnect a plurality, and in any event preferably at least two, closablecontainers 12 having liquid color diaphragm pumps 18 therewithin to agravimetric blender or other device for the direct supply of liquidcolor on demand to the gravimetric blender or some other device,preferably specifically to the weigh pan of the gravimetric blender, asillustrated in FIG. 8.

Continuing with reference to FIG. 8, a gravimetric blender of the typedisclosed in U.S. Pat. No. 6,007,236 and WO97/21528 is designatedgenerally 211. The apparatus for furnishing liquid color material asdescribed above may, but need not, furnish liquid color to gravimetricblender 211. The apparatus for furnishing liquid color as describedabove, when used in conjunction with a gravimetric blender 211, may becontrolled by the microprocessor portion of gravimetric blender 211.

Gravimetric blender 211 includes a hopper, designated generally 212,supported by a frame designated generally 214 which holds a weigh bin215 into which portions of plastic resin material and liquid colormaterial are metered and optionally weighed prior to release into a mixchamber 220. Frame 214 may be a single piece or multiple pieces and asillustrated includes four upstanding members, which are preferably steelangle iron and are identified 230, with two of upstanding members 230being shown in FIG. 8. Frame 214 preferably further includes websconnecting upstanding members 230 together to provide rigidity. Thesewebs have not been illustrated.

Hopper 212 preferably has multiple internal compartments so that aplurality of different solid resinous materials may be dispensed fromhopper 212 into weigh bin 215 preferably by orientation of suitableslide gates or other valve apparatus designated generally 219, locatedat the bottom of a given compartment of hopper 212. Hopper 212 may alsobe provided as a plurality of individual hoppers, each having only asingle compartment.

Gravimetric blender 211 preferably further includes pneumaticallyactuated pistons 221, housed within cylinders 217. Pistons 221 areconnected with hopper 212 via slide gates 219. Pistons 221 arepneumatically powered and operate in response to signals to move slidegates 219 thereby to release material stored within hopper 212downwardly towards weigh bin 215. The pneumatic piston-cylinder actuatedslide gate combinations are designated generally 218 in FIG. 8.

Alternatively, one or more auger feeders may be used in lieu of aportion of hopper 212 and an associated slide gate. Auger feeders aredesirably used for components which are added in amounts of five percent(5%) by weight or less to the mix blend; however, auger feeders add tothe cycle time for each batch and reduce overall throughput rates.Hence, auger feeders are desirably optionally used only for addition oflow weight percentage components to the blend to be mixed.

Positioned within and preferably slidably retained in place by frame 214below weigh bin 215 is a mix chamber 220 having a mixing agitator 222rotatably disposed therewithin. Agitator 222 is mounted for rotationabout an axis preferably shared with a drive motor 226. Motor 226preferably has its drive shaft positioned to drive mixing agitator 222about the common axis. Drive motor 226 is preferably supported by acantilever support, which has not been illustrated in the drawing forclarity, extending laterally from an upstanding member 230 of frame 214.Mix chamber 220 may be preferably fabricated to be slidably removablefrom frame 214 with mix chamber 220 preferably being moveable in adirection parallel with the axis of agitator 222. Blender 211 may bepositioned to furnish blended resin material directly to a molding pressor extruder.

A major advantage provided using the closable container 12 with liquidcolor and a diaphragm pump 18 therewithin together with the driplessconnection apparatus 140 of the type illustrated in FIGS. 6 and 7 isfacilitation of automatic changeover from a first closed container ofliquid color material to a second closed container of liquid colormaterial when the first container is exhausted without interrupting thesupply of liquid color material to the gravimetric blender, or even to aprocess machine such as a molding press or an extruder.

One such arrangement is illustrated in FIG. 8 where two apparatusaccording to the invention for furnishing liquid color have beendesignated generally 10 and include closable containers 12 having liquidcolor therewithin and diaphragm pumps 18 within the closable containers12. In this arrangement, the pumps 18 within liquid color containers 12are optionally and desirably controlled by the same microprocessor whichoperates and controls the gravimetric blender 211. Liquid color materialand various components of solid granular resin material, for examplevirgin resin material, recycled resin material and additives (whichfurther facilitate the ultimate molding or extrusion process) arerespectively serially dispensed for preselected times with the liquidcolor material being dispensed by actuating a diaphragm pump 18 locatedwithin a container 12. Desirably pump 18 cycles by pulsing in responseto the digital pulses of the microprocessor and the associated clockfunction as the microprocessor regulates the entire resinmaterial-liquid color measurement and blending process.

The blender preferably operates to weigh the contents of weigh bin 215after each of the dispenses of liquid color material and any of thevarious components of solid granular resin material. Each weighingoperation preferably compares measured weight to a predetermined recipeamount weight for a given component most recently added to the weightbin. This process continues with such dispensing for so long as measuredweight of the weigh bin contents compares properly to the predeterminedrecipe amount according to preset criteria. However, pumping is haltedfrom a first container 12 and initiated from a second container 12 usingthe diaphragm pump 18 located within that second container, touninterruptedly continue the dispenses of liquid color and resinmaterial components into the weigh bin of the gravimetric blender,whenever the comparison indicates there has been no dispense of liquidcolor material or an insufficient dispense of liquid color material fromthe first container into weigh bin 215. Having both containers 12connected to blender 211 by dripless connection apparatus 140 permitsthe process to operate continuously, since as first container 12 isexhausted and the pump 18 of second container 12 is actuated, liquidcolor continues to flow through a selected set of telescoping conduitsof apparatus 140 without spillage. Once pumping from second container 12has commenced, first container 12 may be disconnected using apparatus140 and replaced with a fresh, full container 12.

Referring to FIGS. 9 through 12, a preferred volumetric controller 300is shown. Volumetric controller 300 is microprocessor controlled andpreferably dispenses liquid color by volume.

Volumetric controller 300 controls movement of diaphragm 36 in a mannerto accurately dispense a measured amount of liquid color. Whenvolumetric controller 300 is used as an alternative to furnish liquidcolor to gravimetric blender 211, volumetric controller 300 preferablyreplaces piston-cylinder combination 60, rod 66, cylindrical adapter 62,and input line 74.

Volumetric controller 300 preferably includes a cam 301, a cam follower302, a vertical oriented pin 303, a spool 304, and a motor 305. Theoutput shaft of motor 305 extends through cam 301 and is held in placeby a cam cap 306 within a cam housing 307, retaining in place by camhousing screws 308 together with a cover 309 and cover screws 310.

Cam 301 has a varying outer surface radius and a constant radius innersurface. The radius of the outer surface of cam 301 gradually increasesover almost three-hundred sixty (360) degrees and then abruptly dropsdown to its initial value. Motor 305 is preferably a D.C. motor.

Cam follower 302 preferably comprises a roller which is in ridingcontact with the outer surface of cam 301 and is secured via rollerscrew 316 to the top of pin 303. The bottom of pin 303 is in contactwith the top of spool 304. As shown in FIG. 12, the bottom of spool 304has a passageway extending approximately halfway through spool 304. Thetop of actuator rod 56 extends into this passageway.

Volumetric controller 300 preferably further includes mounting brackets311, mounting ring 312, and a cylindrical adapter 313 for securingvolumetric controller 300 to closeable container 12. Mounting ring 312is annular and has an inner radius sized so that pin 303 may passthrough the center of ring 312 and make contact with the top of spool304. Mounting ring 312 is attached to mounting brackets 311 with screws314.

Cylinder adapter 313 is preferably adapted to rest inside containerinterior cylinder 54 of container 12, and thus has a outer diameterslightly less than the inner diameter of cylinder 54. A pair of radiallyopposed positioning screws 64 extend radially inwardly within cylinder54. Adapter 313 has a pair of radially opposed slots 315 that openvertically downwardly and correspond to screws 64. Slots 315 extendaxially within adapter 313 and then turn ninety degrees (90°) and extenda short distance angularly around cylindrical adapter 313. These slotsextend entirely through the wall of adapter 313. The openings of slots315 are positionable for engagement with screws 64. An advantageousfeature of this connection is that volumetric controller 300 is adaptedto connect to container 12 without any tools or significant timecommitment. The connection process is a simple “twist and lock” motion.

Referring to FIG. 13, motor 305 is preferably managed by on-board drivecontrol means 350 including an electronic controller 351, a memory 354which is preferably of the type which may be written over to replace oneset of data and instructions stored therewithin with another, and atleast one user input device 352 and/or external input/output connection353 Electronic controller 351 is preferably pre-programmed with theparameters of cam 301, including for example, dimensions relating to theminimum outer diameter of the cam, the maximum outer diameter of thecam, the parameters of the increase in outer diameter of the cam, andthe drop in cam outer diameter.

Electronic controller 351 is also pre-programmed with informationrepresentative of the volume of liquid color that diaphragm pump 18evacuates with each complete and/or partial rotation of the output shaftof motor 305. Other preferably pre-programmed information includes thevolume of liquid contained in container 12 when full, as well as analgorithm for ascertaining the remaining amount of liquid color afterdiaphragm 36 has displaced a measured amount of liquid color. Theelectronic instructions are preferably hard-wired into electroniccontroller 351 and/or stored in write-over memory 354. A user candynamically program electronic controller 351 with these and otherinstructions.

For example, electronic controller 351 can be dynamically programmablevia user input device 352 or be in communication with electroniccontroller 351 via input/output connection 353. Controller 351 mayinclude a scanner (not shown) that reads instructions.

Input device 352 is used by an operator to program a specific volume ofliquid color to be dispensed by diaphragm pump 18 driven by motor 305.Input device 352 is preferably an on-board volumetric controller 300 andmay include, for example and without limitation, on/off switches,buttons, alphanumeric keyboards and thumb-scroll devices. Volumetriccontroller 300 may include a display screen (not shown) that displaysinput, status and other information.

Electronic drive control means 350 may be utilized for indirectlyregulating flow of liquid by regulating actuation, speed, acceleration,etc. of motor 305. Control signals may be sent from electroniccontroller 351 to motor 305 in response to instructions. Theseinstructions are provided to electronic controller 351 from memory 354,via connection 353 and/or user input device 352. Electronic controller351 receives pumping instructions from one of these sources, usesalgorithms and constant values to identify the volume amount of liquidin container 12 at that moment, and sends a control signal to rotate theshaft of motor 305 in a manner calculated to ultimately causedisplacement of a desired volume of liquid.

As motor 305 rotates in response to a control signal, cam 301 is rotatedand the portion of the cam surface in contact with the roller 302changes. Roller 302 contacts the outer surface of cam 301 in a mannerthat roller 302 rides against cam 301 as cam 301 rotates in response torotation of the output shaft of motor 305. Due to the increasing radiusof cam 301, roller 302 and pin 303 are pushed downward to the extendedposition between roller 302 and the central axis of cam 301.

FIGS. 11 a and 11 b show roller 302 contacting cam 301 in both an upwardand downward position. A second follower, e.g. a second roller, may beused simultaneously with the first follower and also connects to the topof pin 303. Because the bottom of pin 303 is in contact with the top ofspool 304, the downward motion of pin 303 causes downward motion inspool 304 and actuator rod 56, and eventually diaphragm 36.

After downward motion of diaphragm 36 displaces the liquid color,diaphragm 36 moves upwards due to its own restoring force as well asforce exerted by spring 38. This in turn forces actuator rod 56, spool304, and pin 303 upward. This forces roller 302 upward, facilitatingcontinuous contact with cam 301 when the outer surface radius of cam 301abruptly drops from a maximum value to a minimum value. Thereciprocating motion of diaphragm 36 repeats itself so long as motor 305is actuated.

If desired, multiple containers 12, each with a corresponding volumetriccontroller 200, can be slaved to a single master. For example, a firstcloseable container 12 can be attached to a first volumetric controller300 having a first electronic controller 351, while a second closeablecontainer 12 can be attached to a second volumetric controller 300,having a second electronic controller 351 (not shown). Both may beslaved to a single external device (master) via their respectiveinput/output connections 353.

The single external master is then used to send and receive controlsignals to each of the electronic controllers, switching off motor 305(and hence diaphragm pump 18) of the container which is low on liquidcolor, for example, and switching on the motor 305 (and hence diaphragmpump 18) of a full container. The external device can alsosimultaneously control output volumes of several containers 12, eachcontaining different liquid colors. When all slave containers are emptyor have run low on liquid color, a signal is preferably communicatedfrom electronic controller 351 to the master to indicate to remotepersonnel that the container(s) 12 needs to be changed.

While pneumatic power is the preferred form of power for the diaphragmpump in accordance with the invention, electrical, mechanical orhydraulic actuation of diaphragm 36 may also be provided.

While diaphragm pump 18 has been illustrated in all cases as beingwithin liquid color container 12, diaphragm pump 18 might be locatedonly partially within or even outside a suitable container 12.

While the interior portion of pump body 24 has been illustrated with aparticular stepped generally cylindrical configuration, other shapes,both tapered and non-tapered, may also be utilized. Likewise, whilesprings 38 and 68 have been illustrated as coil springs, other springforms and sources of bias such as leaf springs, bow springs and the likemay also be used.

An advantage of the embodiment of the invention illustrated in FIG. 1 isthat since pneumatic power is not introduced in the interior ofcontainer 12, there is little risk of leakage of liquid color materialout of container 12.

While the liquid color diaphragm pump 18 has been illustrated as adiaphragm pump, a piston pump might also be used. However, a diaphragmpump is preferable because there is no moving seal, only a flexingdiaphragm which remains fluid tight. If a piston pump were used and thepiston seal leaked air, the leaking air would enter the liquid colorcontainer. Resulting pressure buildup in the liquid color containercould force the liquid color through the check valves and the entirecontents of the container could empty just from the force of the leakingair. Accordingly, diaphragm power is preferable.

1. A method for supplying liquid color material as a portion of plasticresin material to be further fabricated by molding or extrusion,comprising the steps of: a. serially dispensing liquid color materialand resin material into the weigh bin of a gravimetric blender bypumping said liquid color material from a container of the same with adiaphragm pump located in said container according to relative positionof a rotatable cam; b. weighing contents of said weigh bin to determinewhether there has been a dispense of liquid color thereinto; c.continuing to pump from said container as needed for so long as weighingthe contents of said weigh bin indicates there has been a dispense ofliquid color material thereinto but stopping said pumping from saidcontainer and commencing pumping liquid color material from a secondcontainer by using a diaphragm pump located thereon when weighing thecontents of said weigh bin indicates lack of dispense of liquid colormaterial thereinto.